4L60E to 4L80E Wiring Swap
#139
Older Swap
Hey Guys. Great thread with tons of good info. I'm looking for some help on my project... I'm swapping in a 4L80E along with a cammed 5.3 in to my '89 K5 Blazer. I was able to find a '90 3/4 ton Suburban with a TH400 at a local yard that I can grab a transfer case from. It's a NP241C and from what I've been reading it should have the correct input shaft to mate up to the 4L80E and also give me the VSS that I'm going need so I should be good there. My question is with wiring everything up. My engine and harness are from a 2000 Yukon (5.3/4L60E) and the trans is from 2000 Silverado 2500 (6.0/4L80E) so I know I'll need to re-pin the two wires on the trans connector and run an ISS like at the beginning of this thread. What I don't know is if I can just splice together the VSS pig tails from the older transfer case and the newer transmission and call it good or if there's something extra that I need to do. From what I've read online all of GM's transfer cases put out the 40 pulse per minute signal so I'm thinking I should be good there but I was hoping someone could confirm that for me or set me straight if I'm overlooking something. Thanks, Anthony
#140
Here is a couple things I would like to add.
I am swapping a 6.0 and 4l80 into an older pickup and I bought a stock harness online. The harness I got is for a 5.3 and 4l60. Everything is the same other then the trans wiring mentioned in this post.
I pulled the trans plug and removed the S and T pins in the round plug, then moved the U pin into the S pin location. Now I am left with the S(white wire) and T(tan with black stripe) wires. The S wire is pin 79 on the blue connector and the T wire is pin 42 on the green connector. I also need to have 2 wires running from pin 22-23 on the green connector to the Input VSS. I just moved the T and S wires from their pins (42 and 79) and put them in the 22 and 23 pins and them connected them to the A and B terminals on the new Input VSS plug. No need to run more wires.
So swapping 2 pins on the computer, and pulling 2 on trans connector and moving a 3rd. Then adding a VSS connector is all thats needed to swap(other then tuning).
I am swapping a 6.0 and 4l80 into an older pickup and I bought a stock harness online. The harness I got is for a 5.3 and 4l60. Everything is the same other then the trans wiring mentioned in this post.
I pulled the trans plug and removed the S and T pins in the round plug, then moved the U pin into the S pin location. Now I am left with the S(white wire) and T(tan with black stripe) wires. The S wire is pin 79 on the blue connector and the T wire is pin 42 on the green connector. I also need to have 2 wires running from pin 22-23 on the green connector to the Input VSS. I just moved the T and S wires from their pins (42 and 79) and put them in the 22 and 23 pins and them connected them to the A and B terminals on the new Input VSS plug. No need to run more wires.
So swapping 2 pins on the computer, and pulling 2 on trans connector and moving a 3rd. Then adding a VSS connector is all thats needed to swap(other then tuning).